Lecture 7

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School

University of Toronto Scarborough

Department

Environmental Science

Course

EESA06H3

Professor

Nick Eyles

Semester

Winter

Description

EESA06: LECTURE #7 Steep sided, pyroclastic volcano which arent in Iceland because there are basalt volcanoes in Iceland therefore these volcanoes are in Ecuador Went to Ecuador to the Galapagos Islands which are right on the equator and islands in the middle of the ocean; they are a classic example of Hot Spots The islands themselves are just the tip of an iceberg of a plateau that submerges to the east Nazca plates moving to the east and moving volcanoes away to the east and they become eroded and create hot spot trails of old dead volcanoes that have flat tops and are below sea level Volcanoes that have become flat topped and are dead are called Guyouts About 40 hot spots, most of them are on oceanic plates Hot spots usually associated with hot spot islands in the middle of oceans Wanted to know why do we get islands in the middle of oceans and found that the age of the islands: the age of the rocks on the hot spot island are much younger compared to the rocks on the oceanic floor, and the youngest island is right above the hot spot and as you go down the trail you get extinct volcanoes and then eventually they go below sea level Systematic aging of the rocks as you move away from the hot spots and move down the train Orientation of the hot spot trail tells us the direction of plate movement Hot spots played a key role in plate tectonic theory All islands on Galapagos islands have shield volcanoes relatively not dangerous Hot spots is composed of smaller spots Bathymetric map is a map that shows water depth Very fluid basalt coming out of shield volcano, bumps in the middle part which is magma hitting water and are called phreato magmatic eruptions; water will go down www.notesolution.com